Parents will have to help their children pay for their first homes if opposition to house building continues, the housing minister warned today.

In an attempt to stave off criticism of new housing projects, Yvette Cooper said that homes needed to be built in order to tackle "long-term affordability problems" brought on by a growing population and increasing demand for housing.

She warned that it was not just first-time buyers who would feel the pinch if supply continued to fail to meet demand, but that parents of young would-be buyers would have to help their children meet rising property costs.

Ms Cooper said levels of house building needed to reach 200,000 a year to respond to rising demand and affordability problems. Currently, 165,000 homes are built each year compared with 130,000 in 2001.

Government figures show that young people are increasingly choosing to rent rather than buy property, with 41% of under-30s renting and 34% buying in 2006. In 2001, 40% of under-30s bought a home while 33% rented.

Meanwhile, 14,000 people a year are releasing an average of £74,000 equity from their homes in order to buy another property, either for themselves or family members.

Ms Cooper said: "Many people are still opposing the increased housing we need so badly. Yet it won't just be young people who lose out if we don't build the new homes the next generation needs. These figures show their mums and dads will feel the heat too.

"It's also unfair on people who can't get family help to get them started. People's chances of home ownership should not depend on whether or not their parents or grandparents were homeowners before them."

Ms Cooper's comments coincide with a report on the property market published today by the former advisor to Gordon Brown, David Miles, chief economist at Morgan Stanley. Mr Miles predicted a "sharp fall" in house prices in the near future.